Only the 5 xmos chips costs more that 54$ in case you order only 5 of them 
but the Onju doesn’t have that main component.
A little Confused, why are the xmos chips needed and could be go by without using them ?
Then I was also not sure if the Google Nest Mini Gen2 already finished its drop in replacement or what the current status on that is ?
@iMike78 I suggest that you also start a new dedicated thread here in the official Home Assistant community forum as well as in both the GitHub repos about your upcoming Crowd Supply campaign with a good title and introduction to clearify/explain that it for your drop-in replacment PCB for Google Home Mini (not Google Nest Mini) and that it will have almost the exact same feature-set as the Home Assistant Voice Preview Edition, including what the difference will be.
@LuxBoardGames FYI, iMike78 has posted under discussions in his repository on GitHub for his Google Home Mini drop-in replacement board that it is what he currently is focusing on first since the hardware design for that is already complete and that he is about to launch a pre-order campaign on Crowd Supply in just a few days in all goes well. Anyway, the PCB design for the Google Nest Mini (second-gen) board is not finished and iMike88 have put his work with that on pause until after the Crowd Supply campaign for the Google Home Mini (first-gen) board.
Yes it is needed in the use case, please read the original post in this thread as it explained in great detail there and it is explicitly the whole point with this thread.
FYI, just a heads up that @rauli2780 who calls himself rauli2780 on GitHub as well as RauliConcernedVet on Reddit has announced then he is also planning to try reimplementing a fully open-source drop-in replacement PCB concept based on the Home Assistant Voice PE schematics but for the newer Google Nest Audio speaker (which is the big-brother model released in 2020 that acts as the larger successor to the original Google Home smart speaker and the mini speakers).
He has started his own thread about that in this Home Assistant community forum here:
You can read what he has written so far about his ideas for that project here in his GitHub repo:
And here on Reddit (which looks poorky formatted in a code block so ping @rauli2780 to fix that):
- https://www.reddit.com/r/homeassistant/comments/1qz1pmq/opensource_dropin_pcb_for_google_nest_audio/
It is unclear how serious he is about actually going through with that as got no idea of his skillset or experience in PCB design, so far he only posted prerequisites and specifications he hope to achieve with no indication on progress or plan for the PCB design itself, but he has at least started a discussions forum for it in the GitHub repository for community feedback and input in the public, which I think is great for full transparency, see:
Hardware-wise the newer Google Nest Audio speaker model have a much larger speaker element so the sound quality it could be capable of should be a lot better and much louder volume than the minis. I also believe it might have more space to work on for the PCB design so in theory one could possibly fit additional features, such as example using two ESP32 chips with preferably an ESP32-P4 acting as the main application MCU and the addition of a second ESP32-C6 to act as a dedicated co-processor for wireless communications.
Hi everyone,
Just a quick update - the project has now entered the Crowd Supply pre-launch phase, and the page is live:
Everyone, please subscribe to the project there on crowdsupply.com to show your interest and you will receive email updates about this project via Crowd Supply.
If that first crowdfunding campaign is successful then there is hope that for a matching campaign for Nest Mini as well.
@iMike78 Nice! Suggest you also start a new dedicated discussion thread in Home Assistant’s community forum (also in this hardware section) that would just about your “MiciMike Home Mini Drop-In PCB” crowdfunding campain when the project have officially launched, however recommend consider waiting though until when it can actually be ordered as otherwise you risk people seeing it but missing going back to order.
Wish I could get this now as my family is incredibly annoyed with Gemini and I would love to show them what this can do. I’m to the point where I’d love to rip out everything and replace it with this.
Recommend that you buy at least one of the official ”Home Assistant Voice Preview Edition” hardware devices today to set that up to play with first own your own, as it is just as plug and play if you want to use a other conversation AI agent than the default with Home Assistant Cloud. Read these to start with:
And
The built-in speaker in that offical Home Assistent Voice PE hardware is terrible but you can connect an external speaker if want to test music playback. Regardless it is good enough as a proof-of-concept to configure and try different voice control features before you introduce HA native voice control to your family members.
After many months of development and several iterations of the design, the first MiciMike Drop-In Replacement Board campaign is now live and ready for pre-orders on Crowd Supply here → MiciMike Home Mini Drop-In PCB | Crowd Supply
The open-source hardware in that first campaign is designed repurpose your original Google Home Mini (1st gen) with a new PCB for ESPHome firmware to allow for fully local voice control for Home Assistant.
@iMike78 congratulations on kickstarting your first campaign! Highly recommended that you also start a new dedicated discussion thread about that specific project in this community forum as well.
This is amazing, congratulations on getting to this point!
At £100 for a single unit to the UK it’s not something I can justify. I’ll be keeping a close eye to support as soon as possible.
@iMike78 it would probably be a good idea for you to also start a separate discussion in the Music Assistant community as well even though there is a lot of crossover → music-assistant · Discussions · GitHub
Thank you! Totally fair point on the price - it’s not cheap. For context though, ordering the equivalent from PCBWay at their minimum order quantity of 5 units works out to more than double the per-unit cost. Component prices have been rising sharply, so this is already something of a compromise. Hopefully it’ll make sense for you at some point!
do prices go down over time as more get sold?
I know some other projects like onju-voice on pcbway started very expensive, but now are cheap. they used to be about 80-90 each. now you can get 50 for 60$ assembled by selecting cheaper solder options,
No, it will not go any cheaper. Actually after the Crowdsupply campaign more likely the price will go up. This PCB is way more complex than the OnjuVoice with nearly 300 components, and the prices are rising sharply.
FYI, noticed that funding is currently 1032% funded with 399 backers 593 PCB boards claimed, so seems to be a relative success considering that Google Home Mini is less enticing to build on!
Thinking that if a first-time campaign is successful with a replacement PCB for older Google Home Mini then future campaigns for newer Google Nest Mini, etc. can be more successful! 
Check out the latest Home Assistant Podcast episode about MiciMike with @iMike78 himself:
and
Everyone, remember to do the YouTube thing; Hit the Like-button, subscribe, and share! 
Also note that if you do not want to buy a PCB for the first-generation Google Home Mini then you can still also help him out by sponsoring iMike78's ongoing work on new design for the Google Nest Mini (second-generation of Google's Minis series smart speakers) with coffee money via Ko-Fi:
FYI, there is now less than 2-days left before funding ends for MiciMike Home Mini Drop-In PCB:
For reference, looks like the campaign is currently 1256% funded with 721 PCBs claimed so far:
Do we know if the pinout on the PCB matches the pinout on a V1 USB board? In looking really closely at the funky ribbon cable a V1 Google Home Mini uses, it seems like the signal wires physically line up. Has anyone tried just a short 16 pin ribbon cable?
Great to see the v1 crowd funder is such a success! Is there any update on the v2? I’m desperate to get my hands on them!
FYI, see iMike78’s repo on GitHub and the discussions section there for it, it at least looks like @iMike78 has recently significantly updated/changed the PCB design for the V2 (Google Nest Mini), including experimenting with adding an ESP32-C6 as another microcontroller to the same board (a second ESP32 with a IEEE 802.15 radio taht could for example be used as a remote Thread Border Router via OpenThread RCP):
Anyway, iMike78 has previously written there in those discussions saying that his plan is to make another crowdfunding campaign for a V2 (Google Nest Mini) replacement PCB some time after the initial batch of boards from the first campaign has shipped and been received, (because Crowd Supply do not want you to have multiple active campaigns running at the same time).
I still think that he has the option to keep old campaigns open to offer pre-sales and manufacture more batches if there is enough interest to make more of them.